'99 & up 7.3L Power Stroke Engine and DrivetrainDiscussion of the 99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
How do you determine if the fuel bowl heater is not working? 99.5 F-250 7.3L...It cranked good & strong put nothing, It got cold today enough to snow, truck was not plugged in...The WTS did come on but no start.
As far as the heater goes - you could pull the plug and check for voltage when the key is on. Then check for resistance across the heater. Or, you could pull the cap, pull your fuel pump fuse, and turn the key - use the digital thermometer (finger) to see if its getting the fuel warm.
2003 F-250 XLT Crew Cab 7.3L, Chrome BigTex Grille Guard, Quad pillar - 3 ISSPRO gauges (trans, pyro, boost) and DP-Tuner F6; Roush fuel pressure / temperature / oil pressure gauges, Ford Severe Duty AIS, 31 row 6.0 transmission cooler, ScanGauge II, Marinco mod, Walker BTM
It is difficult to check the heater, as the plastic Connection is both the water in fuel sensor, and a Thermostat, that turns heater on and off.
You can check to see that voltage is getting to the connector, but you have no idea if the sensor is passing the voltage inside the bowl, or if the heater itself is bad.
I have owned a few PSD, and when I bought the last one, I noticed that when cold, it didn't run as good as it should when it was cold, and was effected by #2 fuel far more than it should have been when the engine was warm, but the temps outside COLD.
I pulled my entire bowl, and tested the sensor by ohming it, then putting it in the freezer and ohming it, to make certain it was making the connection when it was cold....it did....I ohmed the heater, and it was open. Tested further, and it was the diode on the heater that was bad.....Not sure why it needs a diode, but I replaced the heater element with a new one....could have just bypassed the diode...
Most people will NEVER know if the heater is not working.....But being I am in tune with my PSD, and have owned a few, and am a mechanic, I recognized the symptoms.
If it weren't for me liking to run straight #2 in the middle of winter, I doubt I would ever have noticed.
The fuel heater is a federally mandated device all automotive diesels must have. It's SOLE function is to heat gelled fuel so it may pass through the filter and allow the engine to start. It doesn't work very well (if at all) for this and has absolutely no affect on the operating of the engine nor cold starts.